Address PR #1218 code review feedback

- Extract duplicated extractMethod into shared historyUtils.ts
- Include response content in search (was accidentally dropped)
- Show Parameters instead of raw Request in expanded view; gate on
  params existing so parameterless requests don't show empty block

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clients/web/src/components/groups/historyUtils.ts

@@ -0,0 +1,8 @@
+import type { MessageEntry } from "../../../../../core/mcp/types.js";
+
+export function extractMethod(entry: MessageEntry): string {
+  if ("method" in entry.message) {
+    return entry.message.method;
+  }
+  return "response";
+}